#1312 Transistor Curve Tracer Basics

Comments · 155

• RA

  @rajive67 · 3 years ago

  One of the best explanations I have seen on YouTube for a Curve Tracer! 💯👏

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• SI

  @simonkormendy849 · 2 years ago (edited)

  That diagonal line drawn on the CRT screen when you put the resistor on the machine is a good practical demonstration of Ohm's Law.

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• PA

  @paulz8750 · 2 years ago

  Almost embarrassed to say at the age of 62, as an electronics person having worked most of my life within large companies where money was no object, including those that made equipment that went on war ships, I never new this equipment existed! Thankyou so much for demonstrating it.

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• GU

  @gumbykevbo · 3 years ago

  Curve tracers are great for understanding how transistors work, matching devices if needed, and characterizing a verifying devices when manufacturing transistors. &nbsp; That said, in my 35 year career as working EE, including the design of hundreds of transistor circuits (with production of maybe 100,000 total boards) I never used one after I left college (and only briefly then). &nbsp; &nbsp;<br><br>I think curve tracers came about because transistors have far more variability between devices sharing the same part number than tubes did, and you really had to have curves for each individual transistor if you wanted to design circuits using your &quot;tube think&quot; years of experience. &nbsp; &quot;Tube think&quot; means optimizing the &nbsp;performance of every tube, because they are expensive, bulky, and power hungry.<br><br> As soon as transistors became cheap (ie. when they stopped marketing radios by how many transistors they had) engineers learned to trade off gain for stability using degeneration (negative feedback) so that the parameters of the transistors became non-critical. &nbsp;If you need more gain, just throw in another stage, &apos;cause it costs only a few pennies. &nbsp;You really need to be doing this for thermal stability reasons anyway. &nbsp; Early texts about transistors had dire warnings about thermal runaway, because it happens all the time if you try to use a tube brain to design transistor circuits.<br><br>Power amplifiers still need to push the limits, so having device curves would be helpful in that case.

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• JA

  @jasona716 · 3 years ago

  Although I&apos;ve never used one, I have a strange fascination of curve tracers. Thanks for posting this, very interesting!!!

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• BE

  @berniegaona9920 · 3 years ago

  Perfect tool when looking for &quot;leaky&quot; transistors.

• ST

  @Stuartrusty · 3 years ago

  I spent many years in the semiconductor test industry. I used the older, bigger brother of the unit shown here, the 575 thermionic valve (vacuum tube) curve tracer. No health and safety with these units, also quite easy to defeat the high voltage safety switch on the 576, the unit used here. <br>The 576 if I remember correctly is capable of 1000V at lethal currents, but pulsed DC. <br>A really useful testing tool and I have fond memories of using these, reliable, virtually bomb proof &nbsp;units.

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• MA

  @MarcelHuguenin · 1 year ago

  This is the best explanation and demonstration of a curve tracer I have seen thus far on the tubes, well done!

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• SI

  @simonbaxter8001 · 3 years ago (edited)

  Fantastic video. Really nice bit of kit. Would be great to have a follow up showing the regions of the curves when operating a transistor as a switch and as an amplifier and why it&apos;s important to work in a specific regions of the curves (amplifiers) to prevent distortion/clipping and to maintain linearity of input to output.

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• DA

  @davidjh7 · 3 years ago

  Great intro and discussion. The curve tracer is also great for demonstrating some concepts that can be hard to get across in words, like the Early voltage, breakdown, saturation, etc. I can see this instrument being used in many future teaching videos.

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• NO

  @noisefilter · 3 years ago

  So far the best explanation of input and output IV characteristics of transistors. Thanks!

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• RI

  @richzzzz · 1 year ago

  this channel is pure gold.